Manufacture of disk wheels



Au 22, 1939. t

w. w. HAMILL 2,170,617

MANUFACTURE OF DISK WHEELS Filed Dec. 2, 1956 0- INVENTOR WlLLlAM WILSON HAMILL I UNITED STATES Patented Aug. 22, 1939 PATENT OFFICE MANUFACTURE OF DISK WHEELS of Delaware Application December 2, 1936, Serial No. 113,788 In Great Britain December 3, 1935 6 Claims.

This invention relates to the road wheels of self-propelled vehicles and to the manufacture thereof.

The kind of wheel with which the present in- ..vention is more particularly concerned is that known as the disk type which includes a hubportion adapted for bolting to a permanent hub, a tire-carrying rim, and an intermediate portion which is often perforated and fashioned so that ;the regions between the perforations present a spoke-like appearance. In some cases the crosssectional thickness of the disk is constant, that is the faces are mutually parallel, while in other cases the said thickness is graduated to diminish outwardly from the region of the hub portion to or towards the periphery, either in a straight line taper or in a curve or otherwise.

So far as I am aware, the methods of manufacturing disk wheels of the aforesaid type having the cross-sectional thickness graduated, as hitherto practised have involved the stamping or cutting of a circular blank from a sheet or plate of metal, accompanied by a considerable wastage of material from the hole in the centre I of the disk and from the right angle corners.

The present invention contemplates forming a disk Wheel by rolling abar of metal so that the cross sectional thickness is graduated across the width of the bar and the metal displaced to go lengthen portions thereof to form an annular disk blank, the ends of whichare subsequently welded together.

Technical and commercial advantages result from manufacturing disk wheels in the manner described. The grain of the metal follows the circular shape of the disk, the cross-sectional thickness can be conveniently graduated and proportioned to stress to allow a more uniform yield and more uniform distribution of stress throughout the radius of the wheel instead of concentrating it near the hub; the initial or gross amount of metal required per disk is less; a saving in cost of material is thereby effected; and the manufacturing processes are economical.

The diminution in cross-sectional thickness outwardly may be applied as a straight line taper or a curve to a selected portion or portions of the radius leaving the middle of the disk where bolted to the permanent hub of constant thickness.

According to a further development of the invention, the tire-carrying rim is formed as an integral part of the wheel disk so that the complete wheel is a single unitary structure. Conveniently this object and structure is realised and carried into the field of practice by the use of a rolled section for the raw material which conveniently approximates to a T section and is treated by reducing its thickness and increasing its linear dimension in the manner described to provide the graduated thickness disk.

For a clear understanding of the invention, reference may be had to the accompanying drawing in which:

Figure 1 and Figure 2 show a length of bar stock before processing.

Figures 3 and 4 illustrate a disk made from the bar shown in Figures 1 and 2.

Figures 5-8 are similar views to Figures 1-4 but of a modification having the tire-carrying rim integral with the disk. 7

Figure 9 shows in cross-section the wheel of Figure 8 with the tire-carrying rim parts turned into final position.

In order to avoid the large waste of material inherent in the stamping or cutting from a sheet or plate mode of manufacture, I propose to use as the raw material a length of strip metal or bar the linear dimension of which approximates to the perimeter of the disk bore and the thickness of which is constant. By rolling or other process, the cross-sectional thickness is graduated tapering across the width of the strip, and at V the same time the metal is displaced to lengthen correspondingly the regions that are reduced in thickness until a stage is reached when the longer edge of the blank approximates to the peripheral diameter of the finished disk. Accompanying the thickness-reducing and concurrent length-increasing process is a change in the configuration from a rectangular one to a circular annular one whereby finally is produced an unjoined disk blank which is then subjected to a welding operation to join and integrate the two adjacent radial edges.

The commencing and finishing volume of metal contained in the disk Figures 3 and 4 being the same or substantially the same, the width and thickness of the bar I are determined by reference to said volume and to the length 2 which approximates to the circumference of the hole 3 in the disk centre. After undergoing the rolling processes described, the abutting radial end faces 4 of the disk 5 are welded by any suitable method.

In the known manner, perforations may be made in the intermediate portion 6 of the disk and the metal between the perforations pressed up to a shallow spoke-like shape in emulation of spokes. Also in known manner, the perforations may be produced by a die shaping operation to press out on the rear or inside face of the disk, flanges which border and surround the perforations and improve the resistance to deflection against lateral stresses.

Figures 5-9 depict the development of the invention before-referred to which utilises a T shaped blank I as the raw material and by which the wheel disk includes the tire-carrying rim as an integral part. The upright limb 8 of the blank ultimately forms the disk portion of the wheel, and the transverse limb 9 the tire-carrying rim. As the transverse limb is subjected to rolling, it can be formed to a rolled cross-section having a shape which presents advantages in proportioning strength or thickness to stress, and thereby allows weight to be reduced. Graduation of cross-sectional thickness can be applied to the bed l0 and side walls H of the tire-carrying rim analogous to that applied to the main disk portion l2 the thickness being greatest at the zone of juncture of the disk and rim and diminishing in a straight line taper or a curve to the minimum near the outer ends of the transverse limb. At said ends, the known bead formation Hi can be included by rolling the limb; or the well base part IU of the rim may be of constant thickness and the taper applied to the side walls I I.

After the strip has been converted to annular form by the thickness-reducing and length-increasing method described, the tire-carrying rim part undergoes rolling and other operations to displace the side walls and bring the rim to the desired configuration shown in Figure 9. Such a one-piece wheel represents an important advance in the art of making disk wheels.

As with the first-described embodiment, the intermediate section of the disk may be perforated and shaped in the semblance of shallow spokes.

Having thus described my invention, what I claim is:

1. The manufacture of disk wheels for self-' propelled vehicles from a length of flanged bar stock which comprises fashioning one flange of the bar into a disk by changing the cross-sectional thickness of said flange and varying the lengths of the parts that are changed in thickness, and fashioning the other flange of the bar into a tire-carrying rim part.

2. The method'of forming disk wheels of tapered cross-section from strips of stock having an upright limb and a transverse limb, which comprises bending the strip substantially in the plane of the upright limb to form an annulus and to simultaneously cause displacement of the metal in the regions which are increased in length whereby to taper the cross-section of the upright limb and to decrease the thickness of the transverse limb, and finally welding the adjacent ends of the annulus.

3. The method of forming disk wheels of tapered cross-section from strips of stock having an upright limb and a transverse limb, which comprises fashioning the upright limb into a disk by graduating the cross-sectional thickness of said limb and simultaneously lengthening the portions which are reduced in thickness, fashioning the transverse limb into a rim part by reducing the thickness thereof and simultaneously lengthening the portions which are reduced in thickness, and joining the adjacent edges of the wheel.

4. The method of forming disk wheels of tapered cross-section from strips of stock having an upright limb and a transverse limb, which comprises fashioning the upright limb into a disk by graduating the cross-sectional thickness of said limb and simultaneously lengthening the portions which are reduced in thickness, fashioning the transverse limb into a rim part by progressively decreasing the cross-sectional thickness thereof outwardly in both directions from the juncture of the upright limb and the transverse limb, and finally joining the adjacent edges of the wheel.

5. The manufacture or disk wheels for selfpropelled vehicles from a length of T-section stock, which comprises displacing metal in the upright limb of the stock to simultaneously graduate the cross-sectional thickness of said limb and lengthen correspondingly the regions that are reduced in thickness, said thickness-reducing and length-increasing process being accompanied by a change in the configuration from a straight length to circular annular to produce an unjoined disk blank with the tire-carrying parts integral therewith, and finally welding the adjacent radial edges of the blank.

6. The manufacture of disk wheels according to claim 5, which also includes displacing the transverse limb outwardly to form the side walls of the tire-carrying rim.

WILLIAM WILSON HAMILL. 

